This invention relates generally to fittings for use in dispensing liquid from containers and more particularly to valved fittings allowing only one-way dispensing of liquid from containers.
It is common in the field of liquid chemicals to sell such liquids in reusable containers. Such containers typically will have one or more threaded openings for receipt of a tamper-evident fitting, and the fitting may have a one-way valve therein for preventing the user of the container from contaminating the liquid therein, while still allowing removal of liquid from the container. Fittings are known which allow attachment of a "dip tube" extending down into the container from the fitting, and typically a hose will be attached to an opening on the fitting for pumping liquid from the container, through the "dip tube" and fitting, to a remote point of application. This method of liquid extraction from the container inevitably leaves a small residual amount of liquid within the container.
Other methods of extracting liquid from a container are also known, the most common being to place a fitting on the side or bottom of a container and using the forces of gravity or pressure within the container to drain liquid from the container through the fitting. If a fitting on the bottom of the container extends any substantial distance into the container, a residual amount of liquid will not drain from the container.
Containers of liquid also are often stacked, one upon another, for shipment or storage. Such containers typically have a lip or sidewall extending above the top of the container, thereby protecting any upwardly extending necked opening from damage during shipment while the containers are stacked. It would be highly undesirable if a fitting which is placed in the necked opening of the container during shipment, together with any cap closing the fitting, were not of a "low profile" design and prevented the stacking of containers during shipment or storage.
Additionally, while it might be possible to design a fitting which solved only one of these problems, it would be undesirable if separate and different fittings were required for each particular end-use of the container, i.e., one type of fitting for use with a "dip tube", and another type for use in applications which use the forces of gravity to empty an inverted container. It is also highly desirable that any such fitting be capable of a high flow rate of liquid therethrough for rapid dispensing of liquid from the container.
The foregoing illustrates limitations known to exist in present container fittings with one-way valves. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.